The present invention relates to a positioning system for at least one tubular element connected to a cup-shaped member, wherein the positioning system comprises a positioning mechanism adapted to hold the cup-shaped member and the tubular element in a parking position in a magazine when the cup-shaped member is not used and to allow a pull out motion of the cup-shaped body and the tubular element from the parking position to an attaching position on a teat of an animal.
Teat cups are usually provided with a milk tube and a pulse tube. In automatic milking system, the teat cups are attached to the teats of a cow by means of a robot arm. The robot arm grips the teat cups in a teat cup magazine and moves them to a respective teat of the cow. During this motion, the milk tubes and the pulse tubes of the respective teat cups are pulled out from the teat cup magazine. It is important that the tubes are not pulled out to a too long length such that they come in contact with a floor surface on which the cow stands. In this case, there is a risk that the cow steps on the milk tube and the pulse tube and blocks the flow in the tubes. There is also a risk that the cow kicks on the milk tube and the pulse tube so that the teat cup becomes detached from the teat. In both cases, a teat of the cow will not be completely milked. It is also important that the milk tube and the pulse tube have a release length such that the teat cup will hang substantially vertically downwards from the teat when it is attached to a teat. If the tubes are pulled out to a too short length the tubes will exert a lateral force on the teat cup. In this case, the milking process may be disturbed and the teat cup risks being detached from the teat.
Different cows in a herd have the teats at different levels above the ground surface when they are in a standing position. When cows, having the teats at a low level above the ground surface are milked, there is an increased risk that the tubes of the teats cups will come in contact with the floor surface in the milking stall. Furthermore, the cows are usually able to stand in somewhat different positions in relation to the teat cup magazine during a milking process in a milking stall. Thereby, the distance between the teat cup magazine and the cow may vary even during milking processes of one and the same cow. In view of these facts, it is difficult to find a predetermined release length of the milk tube and the pulse tube which is suitable to use during all milking processes in a milking stall.
In an automatic milking system having a robot arm permanently arranged in a milking stall, the above mentioned problem has been solved in the following manner. When the robot arm fetches and attaches the teat cups to the teats of a cow in the milking stall, the milk tubes and the pulse tubes of the teat cups are pulled out such that they will have a relatively long length. Thereby, there is no risk that the tubes will be too short. During the following milking process of the cow, the robot arm holds the tubes of the teat cups in a lifted state such that the tubes do not risk coming in contact with the floor surface in the milking stall. However, this solution does not work in automatic milking system having a robot arm attaching teat cups to cows in a plurality of milking stalls on, for example, a rotary milking platform.